Method of making hollow construction members



H. JUNKERS. METHOD OF MAKING HOLLOW cowsmucnom MEMBERS.

APPLICATION FILED JUNE 28' I920.

PatentedSept. 5, 1922.

2 SHEETS-SHEET l- J j H. JUNKERS. METHOD OF MAKING HOLLOW CONSTRUCTIONMEMBERS.

APPLICATION FILED JUNE 28,1920. I

Patented Sept. 5, 1922.

2 SHEETS-SHEET 2.

Patented ept.5,1922.

STATES HUGO JUNKERS, 0F DESSAU, GERMANY.

METHOD OF MAKING HOLLOW CONSTRUCTION MEMBERS.

Application filed June 28 To all whom it may concern Be it known that I,HUGO JUNKERs, a citizen of the German Empire, residing. at Dessau,Germany, have invented certain new and useful Improvements in Methods ofMaking Hollow Construction Members (Germany, March 12, 1917), of whichthe following is a specification.

This invention relates to a method of connecting hollow constructionmembers and more especially tubular or other comparatively long membersor bearers, which do not serve for conducting liquids, but fortransmitting forces (traction, pressure, flexure) and whose differenceof circumferences is so great that the inner periphery of one member isconsiderably longer than the outer periphery of the other member, sothat the members on being inserted concentrically one in the other, donot contact with each other.

Until now, when connecting tubes or the like for the sole' purpose ofproducing a rigid connection, the same connecting methods were employed.which are usual in pipe or tube systems serving to conduct liquids.

\ For instance the circumferences of said tubes were changed byenlarging or upsetting these tubes in such a manner that they could beslipped into each other without leaving any free space between them. Inother cases special connecting members such as the so-called reducingjoints have been employed for connecting such tubes.

The first named method of changing the circumferences can be appliedonly tocertain materials well suited for expanding or upsetting withoutcracking or breaking and moreover requires expensive manual labour orspecial contrivances. The method of employing special connecting membersresults in a very undesirable accumulation of constructive parts at theconnections and increases the weight of the structure as a whole.

It is further known to connect two tubes, the inner diameter of the onetube being about equal to the outer diameter of the other one, so thatthe adjoining peripheral faces of the tube ends contact with each other,by forming indentations at the joint, whereby the material is stretchedin this place.

In contradistinction thereto the purpose of my present invention is toconnect tubes whose me ers d ffer so Widely th t a 1920. Serial No.392,586.

sired manner, for .instance, by riveting,

electric point welding or the like. In the drawings affixed to thisspecification and forming part thereof different connections of tubesproduced in accordance with my invention are illustrated by way ofexamples.

In the drawings Fig. 1 is a longitudinal section and Fig. 2 is across-section on line II-II (Fig. 1) of two tubes of different diametersdesigned to be joined together.

Figs. 3 and 4 are cross-sections disclosing different modes ofinterconnection of such tubes.

Fig. 5 is a crom-section and Fig. 5 a perspective view of a third,

Figs. 6 and 6 similar views of a fourth modification.

Fig. 7 isa cross-section of a fifth mode of connecting the tubes.

Fig. 8 is a longitudinal section and Figs. 9 and 10 are cross-sectionson lines IX-IX and X-X, respectively, of a sixth form of tubular joint.

Figs. .11 and 12 are a perspective View and a cross-section,respectively, disclosing a seventh mode of connection.

Fig. 13 shows part of the outer tube 1n flattened condition.

Fig. 13 is a perspective view of a pair of tubes jointed in another way,and

Figs. 14 and 14 are similar views of a ninth modification.

As shown in Fig. 3 they are connected with each other by forming at theend of the outer tube 1 a number of longitudinal indentations 4 of suchdepth, that they contact with the inner tube 2. Along the lines ofcontact the two tubes are then ri idly connected by rivets '8.

ig. 4 shows a connection of square tubes produced in a like manner. I

In the connection shown in Figs. 5 5.and 6 6 the larger tube retains itsshape, whereas the end of the narrower tube is deformed in such a mannerthat it contacts with the eral lines or longitudinal stretches, alongwhich the tubes can be rigidly connected.

Fig. 7 shows both tubes deformed at the ends, so as to contact with eachother.

Flgs. 8 to 10 illustrate a double connection of the tubes, the end ofthe narrower tube 2 being flattened to touch the inner surface of thewider one (Fig. 9) whose end is in its turn flattened so as to touch thenarrow tube from without (Fig. 10).

Fig. 11 discloses a tube connection correspon ing to Fig. 3, clearlyillustrating the deformation of the outer tube. It will be understoodthat the tubes may also be con-.

nected in such 'a manner that their axes do not coincide. In a likemanner tubes of different cross-section can be connected with eachother.

The novel method may also be applied with advantage to open profiles,such as crescent or U-shaped bars or channels.

Fig. 12 shows an example of the connection of two channel-irons. Herethe wall of the larger channel is depressed in three places, withoutaltering its peripheral length, in such a manner that it contacts withthe smaller channel, the rigid connection by'riveting or the like beingeflt'ected at these points of contact.

In order to effect asaving of weight and a more favorable distributionof forces the ends of the tube are preferably toothed or serratedbetween thelines of contact, as shown for instance in Figs. 13 and 13*.

According to Figs. 14 and 14 the teeth or serrations may differ inlength. The rivet holes 5 can then be disposed on the lines of contact6, indicated by dotted lines, so that the weakening of thecross-section, caused by said rivet holes decreases from the center ofthe point of connection towards both sides.

Mainly on account of the small weight of the connections producedaccording to this invention they are of special advantage in theconstruction of flying machines, quite especially at the wing ribs, theframe and other parts.

I claim 7 1. The method of connecting two hollow construction members ofdifferent diameters, which consists in deforming one of said members atthe point of connection in such a manner that it contacts with the otherin plurality of flattened portions and rigidly connecting the members atthe said portions.

2. The method of connecting two-hollow construction members of differentdiameters,

which consists in deforming both said members at the point of connectionin such a manner that they contact with each other in a plurality offlattened portions and rigidlyconnecting the members at the saidportions.

3. The method of connectin two hollow construction members of di etrentdiam.- eters which consists in deforming one member at the point ofconnection in such aman'r n'er, that it contacts with the other in apluralit of flattened portions longitudinally disp aced relatively toeach other, and rigidly connecting said members at the said portions. I

4. The method of connecting hollow construction members of differentdiameters, which consists in deforming the end of one member in such amanner, that it contacts with the other in a plurality of flattenedportions, cutting away part of the material between said portions andrigidly connecting said members at said portlons.

5. The method of connecting hollow construction members of differentdiameters, which consists in deforming part of each member in such amanner, that the deformed part of each member contacts with anondeformedpart of the other member and rigidly connecting the said members at thesaid parts. I

In testimony whereof I affix m si ature.

HU Q N ERS.

